1. High German (Hochdeutsch): This is the standard form of German used in most of Germany, Austria, and Switzerland. It is the language of literature, education, and government.
2. Low German (Plattdeutsch): This is a group of dialects spoken in northern Germany and parts of the Netherlands. It is often considered a separate language from High German, although it is mutually intelligible with it to some extent.
There are other regional dialects and varieties of German, but High German and Low German are the two major forms.